Practise

Question bank

Original exam-style questions, mapped to your syllabus. Answers are checked for mathematical equivalence and every attempt updates your mastery.

TopicSkillDifficulty

12 questions

SA-OC-MO-0011 markL1 FoundationCalculatorRelative mass

Calculate

M_r

\mathrm{H_2SO_4}

. (

A_r

: H 1, S 32, O 16)

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0021 markL1 FoundationCalculatorRelative mass

Calculate

M_r

\mathrm{Ca(OH)_2}

. (

A_r

: Ca 40, O 16, H 1)

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0032 marksL1 FoundationCalculatorThe mole

How many moles are in

36

g of water,

\mathrm{H_2O}

? (

M_r=18

)

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0071 markL1 FoundationCalculatorThe mole

One mole of any substance contains

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0121 markL1 FoundationCalculatorThe mole

The number of moles in a sample is found by

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0042 marksL2 StandardCalculatorThe mole

Calculate the mass of

0.25

mol of

\mathrm{CaCO_3}

. (

M_r=100

)

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0052 marksL2 StandardCalculatorRelative mass

Calculate the percentage by mass of nitrogen in ammonium nitrate,

\mathrm{NH_4NO_3}

(

M_r=80

; N = 14).

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0062 marksL2 StandardCalculatorThe mole

How many molecules are in

0.5

mol of

\mathrm{CO_2}

? Give your answer in the form

a\times10^{23}

; enter the number of molecules.

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0081 markL2 StandardCalculatorEmpirical formula

The empirical formula of

\mathrm{C_6H_{12}O_6}

(glucose) is

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SA-OC-MO-0093 marksL3 ExamCalculatorEmpirical formula

2.4

g of magnesium combines with

1.6

g of oxygen. The empirical formula is

\mathrm{Mg_xO_y}

. Find

x/y

. (

A_r

: Mg 24, O 16)

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0102 marksL3 ExamCalculatorEmpirical formula

A compound has empirical formula

\mathrm{CH_2}

and

M_r=56

. How many carbon atoms are in one molecule?

Salam Academy Original Practice · Proposed mark scheme

SA-OC-MO-0113 marksL3 ExamCalculatorEmpirical formula

A compound contains

40\%

6.7\%

H and

53.3\%

O by mass. How many hydrogen atoms are in its empirical formula?

Salam Academy Original Practice · Proposed mark scheme